1. Field of The Invention
The present invention relates to a hollow wheel for a sun-and-planet toothed wheel gearing having a toothed sun wheel, a toothed hollow wheel and at least one toothed planet wheel.
2. Description of The Prior Art
In order to realize large gear ratios of rotating shafts in a as small as possible space it is common practice to often apply a sun-and-planet wheel gearing. Thereby, usually a sun wheel, three planet wheels and one hollow wheel are brought to mesh in an axially parallel state. The sun wheel and the planet wheels are thereby conventional gear wheels having an outer toothing while the hollow wheel has an inner toothing.
Specifically the production of hollow wheels with an inner toothing poses some problems. If such hollow wheels are to be produced in large numbers the conventional cutting or machining, resp. operations such as reaming or slotting involve to high costs and are also too slow. If, however, at the same time a high precision and rigidity at as low as possible cost are demanded, molding or injection molding methods can not be considered, either. As a non-cutting working a rolling or pressing could be chosen. But these methods regarding the precision of the shaping of the toothing of hollow wheels also meet their limits.